The invention relates to as holding-down means for fixing battery cells in a battery submodule and to a battery submodule which comprises a holding-down means according to the invention.
Electric energy can be stored by means of batteries. Batteries convert chemical reaction energy into electric energy. In so doing, primary batteries and secondary batteries are differentiated. Primary batteries are only functional once, whereas secondary batteries, which are also referred to as accumulators, can be recharged. A battery comprises in this case one or a plurality of battery cells.
So-called lithium-ion battery cells are particularly used in an accumulator. These are characterized among other things by high energy densities, thermal stability and an extremely low self-discharge. Lithium-ion batteries are used inter alia in motor vehicles, particularly in electric vehicles (EV), hybrid vehicles (hybrid electric vehicle, HEV) as well as in plug-in hybrid vehicles (plug-in hybrid electric vehicle, PHEV).
A generic battery cell is, for example, disclosed in the German patent application DE 10 2012 217 451 A1. The battery cell has a cell housing which is, for example, made from metal. The cell housing is designed prismatically, in particular cuboid-shaped, and formed in a pressure-resistant manner. The battery thus has a positive terminal and a negative terminal for electrical contacting.
A plurality of battery cells are consolidated to form a battery submodule and connected electrically to one another. To this end, the battery cells are arranged in a common housing or box, and the terminals of the battery cells are connected to one another by means of cell connectors. A plurality of battery submodules form a battery.
Holding-down means, which fix the battery cells in the submodule in their position, are known in order to prevent battery cells from moving relative to one another as a result of impacts, for example during transport. Such a movement could lead to the cell connectors tearing off.
A battery module having a plurality of battery cells is known from the American patent application US 2012/0244397 A1. The battery module comprises a latticed frame for receiving the battery cells and retaining straps for fixing the battery cells in the frame.
Furthermore, a battery module is known from the American patent application US 2012/0177970 A1, which has a plurality of battery cells that are arranged and fixed in a latticed frame.
A battery module having a plurality of battery cells, which are connected to one another by means of cell connectors, is likewise known from the American patent application US 2014/0255750 A1.
A battery cell with a metallic housing is disclosed in the American patent application US 2014/0349152 A1. The terminals of the battery cell are thereby insulated from the metallic housing by means of insulators.